Study of sulfonation mechanism of low‐density polyethylene films with fuming sulfuric acid

Abstract

Sulfonation of low-density polyethylene (LDPE) films with fuming sulfuric acid was studied by X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance (ATR) infrared spectroscopy. The ATR spectra showed the formation of CAC double bonds and multiple sulfur atom containing groups for the sulfonation of LDPE films. This led us to propose that the abstraction reaction of hydride ion by sulfur trioxide (SO 3 ) in fuming sulfuric acid might account for the formation of the CAC double bonds. It was considered that after the abstraction reaction, these double bonds react with SO 3 , resulting in the production of alkene sulfonic acids and sultones, along with the formation of sulfate groups as a result of reaction of the double bonds with sulfuric acid. Experimental data by treatment of the sulfonated LDPE films with KOH and thiourea supported the proposed idea, estimating the approximate molar ratio of the products.

Crosslinked inter penetrating network of sulfonated styrene and sulfonated PVdF-co-HFP as electrolytic membrane in a single chamber microbial fuel cell

“…Small square pieces of membranes were kept overnight in 1 M H 2 SO 4 solution. 20 Proton conductivity measurements were done through AC impedence spectroscopy, using a potentiostat (Gamry Potentiostat-600) over a frequency range of 1 Hz to 10 5 Hz, at an applied potential of 10 mV. The remaining solution was titrated with 0.01 N NaOH solution, using phenolphthalein as indicator.…”

“…In effect, SS incorporation resulted in higher water uptake and swelling ratios within 20 membranes, where excess DVB restricted inter chain mobility and thereby reduced the available free volume within the membrane. In effect, SS incorporation resulted in higher water uptake and swelling ratios within 20 membranes, where excess DVB restricted inter chain mobility and thereby reduced the available free volume within the membrane.…”

“…S. Ayyaru and S. Dharmalingam also carried out the sulfonation of polyether ether ketone (PEEK) and used it as a proton exchange membrane (PEM) in a single chamber MFC (SCMFC) [14]. Various studies on enhancing membranes properties have been conducted; for 70 instance, surface modification of polyolefins by sulfonation, photosulfonation, plasma treatment, and radiation grafting have been shown to improve hydrophilicity, adhesion, and other properties within membrane [17][18][19][20][21]. Another group led by Gangrekar, also evaluated the performance using earthen pot as a proton exchange material of microbial fuel cells (MFCs) [16].…”

“…Although, being hydrophobic, various studies on its surface modification have shown increments in water retention capability within the 5 membranes [29][30][31]. Being a low cost novel material, 20 we have examined the efficiency of these membranes in single chambered open air MFCs for bio-energy generation using mixed firmicutes as biocatalysts. This significantly improved the overall performance of the system [32].…”

Photosulfonation of Low‐Density Polyethylene Films

“…[1][2][3][4][5] We have proposed sulfonation mechanism of LDPE films with fuming sulfuric acid where SO 3 reacts with LDPE films to produce sulfonic acid groups via the formation of sultones. [17] Given that the generation of SO 3 occurs during photosulfonation, there might be a possibility of the production of sulfonic acid groups via the formation of sultones in the reaction between SO 3 and LDPE films.…”